Share
Explore BrainMass

Organic Chemistry Bonding

In Organic Chemistry, Bonding refers to the process of a carbon-based molecule forming a chemical bond due to the attractive interactions between two atoms. This attraction may be seen as a consequence of the nucleophilic properties of the substituents binding to the carbon – this is because carbon usually has a net positive dipole (although there are a few exceptions).

In organic compounds, carbon is usually bonded to electronegative substituents. For example, the ketone functional group has an oxygen atom double bonded to the central carbon. Due to oxygen’s electronegativity, the electrons shared within the double bond are pulled towards the oxygen and away from the carbon. This electrostatic phenomenon causes the carbon to possess a partial positive charge. It is this dipole which makes the carbon so susceptible to many of the organic reactions where other substituents can bond to it.

For example, in a typical SN2 reaction (which proceeds in a bimolecular manner), a nucleophile attacks the electrophile (due to the partial positive charge of the carbon) causing the leaving group to leave. This creates a new covalent bond which renders the carbon more stable. However, bonding can take place at a different rate in an SN1 reaction where a carbocation forms. This would form a stronger electrostatic force between the two entities causing them to bond immediately.

The phenomenon of bonding spans the spectrum of all reactions –by using this example of a SN1 reaction, it can be seen that understanding the rationale behind this behavior is crucial to predicting the outcome of reactions as well as three dimensional arrangements of atoms within a molecule.

Alkenes and Forming Polymers

What structural properties allow alkenes to serve as good monomers for polymerization reactions? What are the primary types of chemical bond changes which occur during polymer synthesis employing alkenes monomers?

Common and IUPAC names

1. Give the correct IUPAC and common (where indicated) name for each of the following compounds. (see attached file) 2. Each of the following IUPAC names is incorrect. Draw a line angle structure for each of the compounds and give the correct IUPAC name. a. 2,2 dimethyl-4-ethylheptane b. 1-ethyl-2,6-dimethylcy

products of mass spectrometry and stability

I wonder about a mass spectrometry problem where they define which m/z that would appear for a molecule and why another m/z value does not appear that has a primary radical and a secondary cation. I know that the primary radical is unstable but the secondary cation is more stable than other products. Could one explain this by ra

Why E2 is favored over SN2

Sn2 requires a strong nucleophile while E2 requires a strong base. But relatively compared if you have a very strong base the E2 is preferred. Why is it so? Are there any general enthalpy data or something that explains this? I have searched the interenet for a while without finding any mathematical explanation as for example a

Free Hydroxyl Formation on F-TiO2

Does this paper clarify how holes are able to react with "free" hydroxyl anions to form "free" hydroxyl radicals? I'm having trouble understanding it. http://pubs.acs.org/doi/abs/10.1021/la9903301.

Bonding: 4sp Hybridization

How is it that 4sp orbitals are formed, as described in http://csi.chemie.tu-darmstadt.de/ak/immel/script/redirect.cgi?filename=http://csi.chemie.tu-darmstadt.de/ak/immel/tutorials/orbitals/hybrid/4sp3.html with 4s and 4p orbitals? Specifically, for a material like TiO2, where titanium has a configuration [Ar] 4s2 3d2, why

Chemical Structure and Hydrogen Bonds in Base Pairs

Draw the chemical structure of a correctly base paired G-C pair, then re-draw the pair with a propeller twist (these answers should all be on one page following box 'G'). Identify which hydrogen bonds are strengthened, weakened or left unchanged and why. Repeat the process for a base pair buckle and base opening. In this spec

Electronic Configuration, Formation and Enthalpy of Activation

CHEMILUMINESCENCE: SYNTHESIS OF LUMINOL 1. Define the following terms. a. fluorescence b. phosphorescence c. chemiluminescence d. intersystem crossing 2. What is the difference in electronic configuration of a singlet and a triplet state? ALKYNE FORMATION: DEHYDROBROMINATION OF MESO-STILBENE DIBROMIDE(Prepar

Stereochemical Descriptors

1. Draw a Fischer-projection for each of the sugars and assign the corresponding stereochemical descriptor D or L. 2. Assign stereochemical descriptors (R or S) for the labeled stereogenic centers (a-e) in the anticancer drug Taxol: See attached figures.

Topicity relationship and isomer relationship problems

I have a 2 pages of problems that are a review for an upcoming exam. I have always had trouble with bonds and this topic has me confused. I would appreciate an explanation. Once I see it, I can usually figure it out. Thank you for your assistance.

Identifying Acidic Compounds

** Please see the attached file for the complete problem description ** For the attached pairs of compounds, predict which is the stronger acid and briefly explain why (acidic proton marked in bold type).

Writing Equations for Each of the Given Reagents

1. Write an equation for the reaction of 3-methyl-2-pentene with each of the following reagents: a. hydrogen bromide b. BH3 followed by H2O2, OH¯ c. hydrogen (Pt catalyst) d. KMnO4, OH¯ e. bromine f. H2O, H+ 2. What reagent will react by addition to what unsaturated hydrocarbon to form each of the following comp

The Shapes of Molecules and Ions from the VSEPR Theory

The VSEPR Theory: it is the arrangement of atoms in molecules and ions This theory is applied in the following way: ? Consider molecules (or ions) in which the central atom is covalently bonded to two or more atoms or groups ? Consider all the valence electron pairs of the central atom-both those that are shared in covalen

Cellulose Chemistry

Assuming cellulose with the chemical formula C6H10O5.......what happens if: 1) the cellulose is subjected to concentrated H2SO4 (sulfuruc acid) ---- how is the cellulose molecule/structure modified? and what are the reaction by-products. 2) similarly, what happens if cellulose is reacted with maleic anhydride C4H2O3? Again

Example of Reducing Agent Mechanism

Using Curved arrows to symbolize the flow of electrons, write the mechanism for the steps involved in the conversion of 9-fluorenone to 9-fluorenol with sodium borohydride followed by aqueous acid.

Bonding and Compound Questions

1.) Do all ionic compounds dissolve in water, Do all covalent compounds dissolve in water? answer should be 50 to 100 words. 2.) Do the physical properties of water change when a compound is dissolved in water? If so, which properties change and why? 3.) Do all chemical compounds undergo each type of chemical reaction,i.

Elimination by an E1 pathway

Erythro-2,3-dibromo-3-phenylpropanoic acid undergoes eliminiation by an E1 pathway in water solvent (Part A conditions), but by an E2 pathyway (part B conditions) when acetone is used as the solvent. Why does this happen?

Oseltamivir and Neuraminidase: Interaction and Bonding

Draw a diagram of oseltamivir and label showing which atoms or functional groups could be involved in the binding of oseltamivir to the neuraminidase active site by hydrogen bonding and ionic interactions. Identify what complementary functional group would need to be present in the neuraminidase active site for (a) hydrogen

Compounds with Increasing Boiling Points

A series of compounds with increasing boiling point is listed below. Offer an explanation for this trend. a. Butane (8 degrees C). b. Propanal (56 degrees C) c. 1-Propanol (97 degrees C)

Organic Chemistry Bonding: Stereoisomers Example

2,3-Dibromobutane contains 2 chiral centers. Therefore, the possibility of 4 stereoisomers exists. However, the addition of bromine to an equimolar mixture of cis- and trans-2-butene generates only three stereoisomers. Explain.

Alkynes and Hydration

Alkynes can be hydrated in the presence of acid and HgSO4, by electrophilic addition of a molecule of water to the triple bond. The reaction proceeds by way of a carbocation intermediate. Hydration of acetylene (ethyne) produces acetaldehyde (ethanal). Outline the steps that occur in this transformation.

Carbon-Carbon Triple Bond

Compounds containing a carbon-carbon triple bond undergo the Diels-Alder reaction. Formulate the product formed by the reaction of (E,E)-1,4-diphenyl-1,3-butadiene with diethyl acetylenedicarboxylate.

Infrared Spectrum

The infrared spectrum of the xanthene reduction product contains evidence that demonstrates that conjugation of the rings is still maintained following removal of the carboxyl group. What is this evidence?

Example Questions about Sulfathiazole

Answer the following questions concerning sulfathiazole, below. What is the hybridization of the nitrogen atom in sulfathiazole? Assuming that the sulfur atom is sp2-hybridized, how many -electrons are there in the sulfathiazole ring? What reactivity do you predict for sulfathiazole?

Frontier Orbitals

I have my final exam coming up and I am still utterly lost when it comes to frontier orbits. If you could provide some sort of lesson or overall summary about frontier orbitals, including how they are used in a mechanism, that would be extremely helpful! I figure that even if this is not on the exam, I should not walk away fro

Questions on aldol and claisen reactions

Consider the reaction in model 1. (see attachment) a. What two functional groups are found in the product shown in model 1? b. The term aldol is a contraction of ald and ol. Is this consistent with you're your answers to the previous question? Explain c. How many carbons are there in the aldol product shown in model 1?